Solving 1D Navier-Stokes equation using ode45 MATLAB

Hello everyone!

I am trying to solve 1-dimension, inviscid and compressible Navier-Stokes equations using the ode45 function in MATLAB. I have derived the necessary governing equation and have attached them in the post. I understand that normally these are solved using FDM, FVM etc, but I wish to solve them using ode45 as it would require much lesser computational time.

The equations are coupled and every equation contains a derivative term of another variable which may not be calculated yet. For instance, as per my understanding, if I were create an ode function containing the 4 system of equations as per the order given in the attachment, then ode45 would first try to solve the energy equation (dT/dx) but it wouldn't know the value of the derivative of velocity (du/dx) as it has not been calculated yet, and so the solver would use du/dx=0, which would be incorrect.

Is their anyother way to solve these coupled odes? Kindly correct me if I am mistaken.

[darova]

If i understood you correctly: you have all initial conditions

To calculate next step you need all du,dp.... Solve 4x4 matrix to get them

[Neelay Doshi]

Turns out my equations were not correct but the method you suggested works. Thank you for your response.